This invention relates to implantable prosthesis and, more particularly, relates to subcutaneous gel elastomer implants.
Early on, silicone gel used for cosmetic purposes was in the form of liquids which were injected subcutaneously. However, serious problems developed because of the migration of the silicone gel into surrounding tissue causing granulomas. These problems became so serious that use of liquid gels was all but stopped. To solve the problem of the migration of the liquid gel, several solutions have been proposed and adopted. Among these was the encapsulation of the silicone gel in one or more artificial plastic or silicone envelopes and implanting this prosthesis subcutaneously. This, however, created altogether new problems.
When such implants are used, for example, in mammaplasty procedures, a natural tissue capsule forms around the implant. Since the advent of the envelope-encased implant, doctors have been fighting the problems following these augmentation mammaplasty procedures, particularly because of the firmness caused by the contracture of the natural tissue capsule which is formed and which tightens around the encased implant. The answer to this problem was thought to be an open or closed capsulotomy, leaving the implant intact. The closed capsulotomy procedure consisted of crushing (i.e. breaking up) the natural tissue capsule by manipulation of the tissue or breast. Alternatively, an open or surgical capsulotomy was sometimes performed. However, neither of these procedures have been effective because they do not get rid of the offending foreign body. That is, the body starts the process of forming the natural tissue capsule over again, resulting in contractures producing excessive firmness and deformity and, in some cases, pulling and painful sensations to the patient with distorted and extremely firm results.
One logical way to solve the problem would be to place the implant in the tissue with the envelope and allow it to remain until the natural tissue capsule is formed which usually will occur within approximately six weeks. The silicone envelope could then be removed, allowing the natural tissue capsule to contain the silicone gel without allowing its migration into surrounding tissues. However, of course, this requires a second procedure and there is no guarantee that some migration will still not occur.
Thus, it was determined that the solution to the overall problem was to provide an implant which eliminated the offending foreign body (i.e., the silicone envelope) and provide an implant which would eliminate the possibility of migration.